The invention relates to the field of capacitors in an integrated circuit.
On-chip decoupling capacitors are helpful in compensating for the voltage drop associated with power grid inductance, particularly for high surge current conditions. The inclusion of these capacitors on-chip as opposed to off-chip greatly reduces the affects of the inductance and provides decoupling for higher frequency noise.
In many current semiconductor processes, copper is used as an interconnect material. Often a damascene or dual damascene process is used to form the copper interconnects because of the difficulty in etching copper. As will be seen, the present invention lends itself to fabricating capacitors in conjunction with a dual damascene process.
A dual damascene process for fabricating copper interconnects is disclosed in U.S. patent application Ser. No. 09/746,035, entitled xe2x80x9cMethod for Making A Dual Damascene Interconnect Using a Multilayer Hard Mask,xe2x80x9d filed Dec. 22, 2000 and assigned to the assignee of the present application.